APOD: Phaethon's Brood (2017 Dec 23)

Comments and questions about the APOD on the main view screen.
User avatar
APOD Robot
Otto Posterman
Posts: 3484
Joined: Fri Dec 04, 2009 3:27 am

APOD: Phaethon's Brood (2017 Dec 23)

Post by APOD Robot » Sat Dec 23, 2017 5:10 am

Image Phaethon's Brood

Explanation: Based on its well-measured orbit, 3200 Phaethon (sounds like FAY-eh-thon) is recognized as the source of the meteroid stream responsible for the annual Geminid meteor shower. Even though most meteor showers' parents are comets, 3200 Phaethon is a known and closely tracked near-Earth asteroid with a 1.4 year orbital period. Rocky and sun-baked, its perihelion or closest approach to the Sun is well within the orbit of innermost planet Mercury. In this telescopic field of view, the asteroid's rapid motion against faint background stars of the heroic constellation Perseus left a short trail during the two minute total exposure time. The parallel streaks of its meteoric children flashed much more quickly across the scene. The family portrait was recorded near the Geminid meteor shower's very active peak on December 13. That was just before 3200 Phaethon's historic December 16 closest approach to planet Earth.

<< Previous APOD This Day in APOD Next APOD >>
[/b]

Boomer12k
:---[===] *
Posts: 2440
Joined: Sun Apr 22, 2007 12:07 am

Re: APOD: Phaethon's Brood (2017 Dec 23)

Post by Boomer12k » Sat Dec 23, 2017 9:26 am

Violet Stars.... interesting image...

:---[===] *

heehaw

Re: APOD: Phaethon's Brood (2017 Dec 23)

Post by heehaw » Sat Dec 23, 2017 2:53 pm

Neat!

User avatar
bystander
Apathetic Retiree
Posts: 18138
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Re: APOD: Phaethon's Brood (2017 Dec 23)

Post by bystander » Sat Dec 23, 2017 4:09 pm

Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

User avatar
Joe Stieber
Science Officer
Posts: 156
Joined: Tue Aug 18, 2009 1:41 pm
Location: Maple Shade, NJ

Re: APOD: Phaethon's Brood (2017 Dec 23)

Post by Joe Stieber » Sat Dec 23, 2017 9:25 pm

I'm generally dissatisfied when the APOD doesn't provide any specific information about the date and time of a picture, especially for a transient object such as (3200) Phaethon, or any information about the size or specific location of the field-of-view being presented. Furthermore, I couldn't find a link in the text that went to a photographer's page which elaborated on the background information. So, I looked at Phaethon's path in SkyTools for an observer in Tokyo, Japan, and by matching the star field, I found the picture corresponded with the following...

It was taken about 1:30 am local time on December 14, 2017 (16:30 UT on December 13, 2017). Phaethon would be moving from left to right as seen here. The bright star just left of center near the top of the frame is 36 Persei, magnitude 5.3. Celestial north is slightly left of being directly up and the frame is very close to 3°wide x 2°high. If not cropped, that would represent an approximate 685 mm focal length with a "full frame" DSLR or a 425 mm focal length with an APS-C DSLR (of course, it could have been some other type of camera).

The meteor tracks do indeed lead back to Gemini, about 45°off to the left in this view.